Recycling methods for glass fibre-reinforced plastic polymers : Glass fibre composites in a circular economy?

Sammanfattning: The reinforced composite industry is expanding. This raises the need for more sustainable resource use and waste management. A concept to combat both is circularity, creating a loop between the raw resources and the waste. Two important parts of circularity are recycling and reusing. This thesis presents literature studies on recycling, reuse and end-of-life methods for glass fibre-reinforced plastic composites, specifically with a thermoplastic matrix. The focus lies on preserving the reinforcement properties and either recovering the plastic matrix or its energy. Several viable methods were found, divided into thermal, chemical, mechanical, and other. The majority of the processes for thermoplastics can preserve the reinforcement properties while re-melting the polymer and reusing it. The main problem still is the novelty of the techniques and how to introduce them efficiently to the current composite supply chain. There is also a wider range of recycling techniques for post-industrial waste, posing the concern for post-consumer waste. Routes that can treat contaminated materials while still recovering their reinforcement properties are a subject for future research. There are also gaps in how to make it economically feasible and compete with inexpensive virgin materials. Despite the obstacles ahead, this thesis concludes that there are several potential routes on its way to becoming commercialised and this research field has just started uncovering knowledge to make the life of composites more circular.